Refrigerating machine



2 Sheets-Sheet l .ml u r .nn-m n n WA if w h5 W e .vn .mm H r ,4h C @A rs1-m April 18, 1933 c. sTl-:ENsTRUP REFRIGERATING MACHINE Original Filed May 18 1926 April 18, 1933. C, STEENSTRUP 1,904,559

- REFRIGERATING MACHINE Original Filed May 18. 1926 2 Sheets-Sheet 2 b5 His ATToneH.

Patented Apr. 18, 1933` CHRISTIAN STEENSTRUP,

. ELECTRIC COMPANY,

OF SCHENECTADY, NEW YOB A CQRTOBATION F Assioma "ro ummm New vom; V

REFBIGERATING MACHINE Application. led vMay 18, 1926, Serial No. 109,960. Renewed February 6,' 1931.

, My invention relates to refrigerating apparatus, and particularly to refrigerating machines of the type es ecially adapted for domestic use and an ob]ect of my invention .is the provision of an improved machine of this character which shall be simple in construction, quiet and efficient in operation, durable, manufacturable at relatively low cost and .have other desirable qualities which adapt it for such use.

The machine involving m invention employs a refrigerant which oils at a relatively vlow temperatureand'is caused to pass `through a cycle which consists in allowing the refrigerant in the liquid form to evaporate and thus absorb heat, compressing t vaporizedV refrigerant, and removing the heat therefrom to cause it to condense into the liquid form again, this cycle being continuously repeated during the operation of the machine.

o My invention will be better-understood from the following description taken in connection with the accompanying drawings, and its scope will be pointe out in the appended claims.

Referring to thedrawings, Fig. 1 is a vertical sectional view of a machine embodying my invention; Fig. 2 is a cross sectional 30 view thereof taken on the line 2-2 of Fig.

v 1; Fig.'A 3 is an enlarged fragmentary view of Fig. 1; Fig. 4 is a cross sectional view of parts shown in Fig. 3; Fig. 5 is a fragmentary cross sectional view taken on line 5--5 35 o f Fig. .4; Fig. 6 is a cross sectional view ftaken on line 6-6 of Fig. 2; Fig. 7 is a perspective view with a part broken away of the evaporator; and Fig. 8 is a perspective view of the pistons of the compressor and oil pump.

In the drawings I have shown at 1, by way of example only, the top or cover Aof a refrigerator cabinet such as may form a part of a domestic installation. Mountedon the top 1 is the compressor and cooling unit 2 Vand beneath the top and within the cabinet is the evaporator 3.

' The compressor which in certain respects' is similar to that disclosed in the application 50 of Clark, Orr, Ser. No. 7 56,336, filed Dec. 16,

1924, PatentNo. 1,725,472, and assi ed to the same assignee as the present a p cation, comprises a 'frame 4 in which the rive shaft 5 is journalled and in which the oscillating cylinder 6 havin the exhaust valve 7 is piv- 55' ot'all mounted y means of the trunmon's- 8. he moving parts are enclosed by the metal casing 9Y whose' lower portion 1s enlarged and is connected with the upper portion by the flared portion 9. By means of lugs 10 secured to the exterior of the enlarged portion and bolts 11, the casing is held down tightly against the bottom plate 12, which plate is supported on the top 'l by the angle brackets 1 3. A suitable apron 66 14 covers this plate and the lower part of the casing to present a better ap carence. Fitting in the upper portion of t e vcasing 9 is the stator 16 of an electric motor whose rotor 17 is secured tothe shaft 5. The 70 upper edge ofthe frame 4 is resiliently .held against the stator 16 by. the pins 20 and the coil springs 21.

Surrounding the casing 9 comprising the coil'of pipe 23 is at the top of the casing. A series of fins 24, preferably of good heat conducting material, extend radially from the casing 9 and have their outer edges provided w1 recesses 25 for receiving the separate turns 80 of the condenser coil 22 and making good thermal connection therewith.' The inner ends of the fins are irml secured to and in good heat conducting re ation with the up per portion of the casing 9 by soldering or 85 razing, or in any other suitable manner, and are shown, see Fig. 2, as formed in pairs each with a short connecting portion in contact with the casing. Certain of the fins are firmly secured also to the anchoring lugs 10, whereby they bridge the flared portion 9 and serve to stiffen the casing at this point. The fins 24 intermediate their inner and outer edges each have a r'ow of holes 26 which, as shown in Fig. 1, is'closery tothe 95 outer edge than the inner edge. These holes are preferably arranged quite close together, with onl)1 suicient material between the holes vto 'provide necessary stiffness and mechanical strength for supporting the conis the condenser 22`whose intake 75 denser coil. By these fins, heat is conducted away from both the. casing 9 and the conof heat which it is desired shall be dissipated from the casing containing the compressor 'and the motor is greater than that from the condenser coil, the row of holes is arranged accordingly closer to the condenser coil. By varying the relative position of the row of holes 26, it is possible to regulate to a certain extent the relative cooling effect of the fins on the casing and the condenser coil. The fins 24, therefore, serve the triple' purpose of providing a support for the condenf ser coil, of radiating heat from the casing, and of radiating heat from the condenser coil. A

As shown in Fig. 2, the frame 4 is formed with an arcuatev wall 27 forming a circular cavity centrally within which the cylinder is pivotally mounted. On the sides of the cyl- 5 inder are the radial projections or iins 28, which have sliding engagement with the Wall 27. Thus there is formed an exhaust chamber between the end of the cylinder and the wall 27, and two pairs o-f similar expansion chambers of varyingsizc between the fins 28 and the wall 27, the chambers comprising the first pair4 being larger than the exhaust chamber, and the chambers comprising the second pair being larger than vthe first. At suitable points, the wall' 27 is yprovided with small cut-away portions 27l which, under the. control of the fins 28, permit the compressed refrigerant to pass siiccessively from the exhaust chamber to the first and to the second expansion chambers, and then pass into the main casing. The arrangement, preferably, is such that the oscillatory movement of the cylinder fol# lowing a compression stroke4 admits com-y pressed refrigerant from the exhaust chamber to the two first expansion chambers, and at the same time refrigerant in the two second expansion chambers is allowed to pass the .casing 9.,

into the main casing. As the cylinder oscillates in the opposite direction, and on the compression stroke, refrigerant .may expand lfrom the first expansion, chambers tothe second. Thecompressed refrigerant thereby -undergoes. a series of slight expansions before being deliveredto the space' within which efectually muiiles the sound thereof. l

The vaporized refrigerant, whichis pref erably sulphurldioxide, after .being compressed, passes upward through the motor to the condenser-intakeA 23. As vthe motor employed preferably has a very small air gap, I have provided openings 29 vthrough the rotor 17 for the free passage of the refrigerant. These openings, as will be noted upon reference to Fig. 1, are inclined so that the lower end is at a greater distance from the shaft than the upper end. When the rotor is in rapidfrotation, anyoil particles .which are entra-ined in the compressed refrigerant will be separated out by centrifugal force as they pass through the openings and will be caused to'iow downward or away from the intake 23.

rlhe outlet end of the condenser coil 22 connects by the pipe 30 with casing 3l forniing a floatchamber 32, shown located at a rear corner of the cover 1. fn this chamber is the float 33 (see Fig. 6) which, by means of the lever 34, operates the valve 35 to control tlie flow of liquefied refrigerant to the evaporator through pipe 36.A

Machines of this type are designed to run intermittently `in accordance with the temperature in the cabinet. The starting and stopping of the driving motor is automatically controlled and, when running, the motor vis operated atrelatively high speed.

'ltis highly desirable, however, to have such a machine operate as quietly and as free from vibration `as-possible. ll have therefore devised .improved means for balancing.

the moving parts of my machine such .that

at normal running speednoise and vibra-7"k f tion are reduced to "a very low value .,(seefvv As stated 1n the beginning ofthe F ig. description, the compressor involves a sinmember, shown in the present case as a crank pin 42, which is journalled in a bearing sleeve 43 carried by the piston 41. Be-

yond the, crank pin ll provide the piston with the counterweight portion 44 having such mass that the piston is substantially balanced on the crank pin whereby the center of gravity of the piston and the center of the crank `pin substantially coincide.l lln yconjunction with the above, 'I provide the shaft 5 with the counterweight 45 opposite the crank pin 42 and having such mass that it substantially balances the combined mass ofthe crank pin and the piston. ln this connection, it ,is-to be understood that the part connecting'the shaft and the crank pin is considered as apart of the crankpin. Asso constructed, the moving, parts comprising the shaft, crank pin and piston are so balanced that even though operated at relatively high speed,'bu`t little vibration and noise vare perceptible;

`To provide adequate lubrication of the various moving parts, the cylinder and pis- .ton are partially immersed in a bath 46 of lubricating oil contained in the casing 9 from whichv the oil is forced-to parts argle oscillating cylinder 6 mounted on trunlil@ ' ing oil may freely escape `at a relatively high oillholes in the rotating whose .outer end is fixed to the'piston 41.

- The inner endy of the bore 47is adapted' to connect by the passage 49 alternately with th`e passages 50 and 51 as the cylinder oscillates, whereby oil is pumped from the bath 46 to the lower trunnion bearing, to an oil groove in the cylinder wall and on, up` through passages 52 and' 53 to the oil space 54 surrounding that portion of. the drive shaft between its upper andv lower bearings. Between passages `52 and 53 is the piston 55 'mounted to slide in a suitable bore in the frame 4, and which is raised by oil lpressure from the oil pump Vuntil the` twopassages connect with each other. Oil hole 56 in the shaft 5 leads from the oil chamber 54 down through the crank pin 42 to the bearing 43 therefor. y A second oil hole 57 in the shaft leadsv from the oil chamber 54 Ato the spiral oil groove57, by which oil is supplied to the thrust bearing above, from which bearthroughsuitable grooves, and thus relieve the oil pump of excessive back pressure. It will be noted that. the discharge end of the oil hole 57 is covered by bearing, and that this hole from its entrance to approximately the center' of the shaft 1s of much larger diameter than the remainlng portion. This is for adenite purpose. n the case of a direct connected machine, such `as that illustrated, which is ada ted to run speed, the e ect of cen-- of oil throughv the members must be given due consideration, Should the flow of oil through the oil hole 5,6 leadin to the crank pin, for example, become bro en, the

trifugal force on the flow centrifugal force of oil at the 'entrance to this oil hole may be suicient to prevent its entering the oil hole, since oil hole 57 proi vides a relatively free path of escape for the oil. However, by making the entrance portion'of oil hole-57 of much than the exit portion,

larger portion of. flow of oil through through this hole.

larger diameter and larger than 'hole 56, the larger mass of oil contained in the hole v57 will prevent the this hole until the pres- 54 shall have built up the oil to flow inward Even after` the oil flow sure in the oil space suiciently to cause 1 is established through the holes 5e unam,

a certain predetermined pressure will bemaintained in the space 54 byvreason of the larger size of the entrance holev 57, but this pressure w1ll not rise to such a value as to impose an excessive back pressure upon the oil pump.`

When the machine is restarted after van l .61:5 interval of rest'it'may ha pen, especially if the main piston'is ont el suction stroke,

the lower end of the upper shaft portiony of oil mitted to the cylinder for equalizing the pressures on the front and rear ends of the piston for the first few strokes, at least,.or until the motor has had an opportunity to gain speed. In this connection, reference is had to Figs. 3 'and 4. The suction pi e 58 from the evaporator, after entering the casing 9, connects with the casing 5910i the check valve 60, beyond which it connects by passage 61 with the port 62 of the compressor, thence by intake port 63 to the interior of the cylinder. Equalization of the pressure on opposite sides of the piston is eected by admitting pressure from the space within the casing 9 to the rear endl-of the cylinder. For this purpose, asmall pipe 65 leads from the check valve'casin 59 lto the .plate 66 covering the bore 89 w ere it connects with one side of the valve seatv 67 t mounted therein va valve 70 lightlyl pressed I outwardly by the spring so that when the piston moves upwardly under Vthe pressure of oil, the valve 7() engages its seat while a space still exists between the piston and the plate 66. The arrangement is such that, as long as thepiston is raised an amount suliicient to permit the oil to pass between assages 52 and 53, the valve 7() will be eld a ainst its seat. When the machine stops, the loss of oil pressure permits the piston 55 to descend, thus opening the valve 70 by -whichthe pressure in the casing 9 is communicated with the intakeof the compressor. If `the piston is onl the suction stroke, the intake ports being thus in alinement, the pressures on the two ends of the piston are equalized. This condition will continue for subsequent suction strokes untilv suiicient oil has been pumped to raise the piston 55 and close'off the 'valve 70. Since the intake port 63 is 'spaced slightly from the end of the cylinder, I have provided the cylinder with a small opening 71 close to'the end, whichl suction stroke, with a small opening 72 leading to the port 62.

The evaporator 3, which, as stated above, is locatedwithin the cabinet of which I have shown only the upper portion and the ycover Inl opening connects, when the piston is on the A 1, in the present embodiment, is illustrated in Fig. 7 in the form of la horizontal flat plate, preferably located near the cover 'but spaced therefrom. sl/lfliciently to permit its being used as a sh lf upon which may be placed articles to be" frozen as for example, a tray 73 for making ice cu es. The evaporator'is shown comprlsing a rectangular cas- 36 from the ioat lvalve casing 3l connects` with the evaporator casing at one side there.-

of.v The outlet orxsuction pipe 58 is also shown connecting with the evaporator cas? ing atfonek side thereof, but its connection differs from that of the inlet pipe in that the portion 80 thereof within the casing extends to a point substantially equally distant from the four sides. The evaporator casing is intended to be only partially full of liquid refrigerant, the depth of refrigerant being about one half the depth of the casing. 0n the surface of the refrigerant there may be a thin layerof oil, shown for example in Fig. l of the drawings by the heavier shade lines, the space above the liquid refrigerant and oil being of course filled with vaporized refrigerant.v The pipe 80 is shown having a goose-neck end portion 81, the open end 82 being close to the top wall of the casing, and in the curved portion are several small holes 83 some of Which are located slightly above the levcl'of the liquid refrigerant.

Through these small holes 83 any oil which collects on the surface of the liquid refrigerant is slowly withdrawn. This construetion avoids the necessity of exact leveling of the machine, for since the outlet is located centrally ofy the evaporator casing, there may be considerable deviation from exact level without affecting the relative level of the liquid at the outlet and Without danger of liquid .refrigerant being pumped up by the compressor;

As shownY in Fig. '7, the evaporator is constructed to form a number of "closedchambers 85 therein Whichare filled with a suitable material to constitute a heat reservoir. I provide. the evaporator casing with partitions 86 -Which have Water and gas tight connections with the Walls of the casing and which form separated heat storage units lying .in the vliquid refrigerant. I have shown'the partitions U-shaped with the tvvo free ends-let into a side Wall of the evaporatorcasing. I construct the evaporator in an eiicient and inexpensive manner by forming the sides, topv and bottom of the casing and also thepartitions 86 of separatesheet metal members suitably mechanically secured together and afterward copper brazing in a single. operation all joints by subjecting the entire casing totreatment in a. hydrogen furnace. In this manner, a plate evaporator'may be constructed without the use of gaskets, with a minimum amount of material and at a small labor cost.

Through vplugs 87 in the side Wall to which the-partitions connect, the chambers 85 formed. by the partitions and wall are y space Within the casing 9.

through the inclined' discharge openings` 29 filled with a freezing mixture, after the-casthat in the normal operation ofthe machine` a portion, at least, thereof alternately freezes and thaws, whereby the samevheat storage capacity is obtainable with a smaller amount of liquid than where freezing of the liquid does not occur. In one of the chambers 85 I have shown a thermostat 88 which, by means not shown, controls the starting and stopping of the driving motork in accordance with the temperature in that chamber. By absorbing heat at one time and giving it up at another, the heat. reservoir thus formed serves to' produce a more even temperature in the cabinet and reduces the frequency ofthe operating periods of the machine. Subdivision of the heat res ervoir into spaced units brings the refrigerant into closer thermal relation with the body of heat storage material, whereby a relatively small quantity only is necessary. A further advantage lies in the fact that a greater area for'heat transfer is provided and the depth of the frozen solution on the walls of the units is limited by the width of the units, it being Well'known that by its heat insulating effect a layer of ice-.on the 'walls materially reduces the rapidity of heat A1n the'evaporator 3 is vaporized as a result of heat recei-ved from the surrounding medium. The vapor drawn up throughpipe 58 by the compressor is compressed and discharged through the mufiier formed' at the sides of the compressor cylinder`6. into the Passing up in the rotor of the driving motor, it enters the condensing coil 22 through the pipe 23. The compressed vapor, while in the casing 9', loses a certain amount of heat through the lins 24, and more heat is lost While it traverses the coil 22 through direct radiation therefrom and through the same fins 24. The vapor' finally condenses and flows through pipe 30. into the iioat chamberv 32, from which it escapes through float valve .35 into the'- evaporator 3.

Although I have shown a particular embodiment of my invention, modifications thereof will occur to those skilled in the art. I desire it to be understood, therefore, that my invention is not to be limited to the particular constructions set forth, and I intend in the appended claims to cover all modifinoy cations which 'do not dep in for y casing having an outlet opening,

art from the spirit and scope of my invention.

What I claim as newA and desire to secure by Letters Patent of the United States, is:

1. A refrigerating machine comprising a casing, a compressor therein, a condenser coil surrounding the casing and connected with the compressor, and a series of heat radiating fins on the casing condenser coil.

2. A refrigerating machine comprising a casing, a compressor and a driving motor therefor in the casing, a condenser coil surrounding the casing and connected with the compressor, and a series of radial fins secured at their inner ends to the casing and having openings at their outer ends for receiving the condenser coil.

3. A refrigerating machine comprising a sheet metal casing having two concentric main portions lof different sizes and 'a .Connecting portion, and combined heat radiating and stiifening means for the connecting portion of the casing comprising a plurality of fins in fixed connection with the two main portions of the casing.

4. A refrigerating machine comprising a sheet metal casino having two concentric main portions of different diameters and -a connecting flared portion, a f plurality of anchoring lugs secured to the main portion of larger diameter, radiating and stiifening ins each secured to the main portion of smaller diameter and to the anchoring lugs. v

- 5. lA refrigerating machine comprising a casing, a compressor therein, a condenser coil surroundin thecasing, and a series of heat radiating ns on the casing and in thermal connection with the condenser coil, said fins having means com rislng a row of opene casing and the conture gradient. O

6. A refrigerating machine comprising a casing, a compressor therein, said casing having an opening for the lescape of compressed refrigerant, and a motor for driving the compressor having a rotor within the casing arranged between the compressor and said opening, said rotor having means theretion of oil f rom the refrigerant during .the

,operation of the motor.

'7. A refrigerating machine comprising a v Y a compressor 1 n the caslng, and an electric motor for drivin the compressor having a rotor arin the casing between the compressor and the outlet opening, said rotor having openings therethrough arranged at the normal speed of the rotor to cause oil fparticles entrained in the compressed re r passingl through said opemngs to be sepa range for supporting the Aand a plurality of heaty assing compressed refrigerant, said means emg arranged to cause the separafrigerant and heat storal igerant rated out and to flow away from the outlet opening.

8. A refrigerating machine comprising a' casing having an-outlet opening adjacent the upper portion thereof a compressor in' the lower vportion thereo and an electric motor in an intermediate portion thereoffor drivingthe compressor, said motor having its rotor provided with passages therethrough which are inclined to the axis of rotation, the lower ends of theopenings being at a greater distance from the axis than.- the upper ends thereof.

9. A refrigerating machine having an evaporator adapted to be-partially filled) with refrigerant covered with a layer of lubricant means forming an outletpassage from said evaporator having a main vopening arranged above the level of the lubricant and having means forming an auxiliary outlet for affording communication with said outlet passage atfdiiferent levels of the lubricant for admitting lubricant to said outlet passage upon variations inleve'l of the lubricant in said evaporatorn 10. A refrigerating machinel having an .evaporator adaptedv to be partially filled with liquid refrigerant covered with a layer of lubricant, means forming an outlet passage from said evaporator having a main opening arranged above the level of the lubricant and having a plurality of relatively1 small auxiliaryopenings; arranged at di ferent levels below said main opening and approximately at the level of the lubricant for admitting lubricant to said outlet pas-- sage upon variations of the lubricant level in said evaporator.

11. A refrigerating machine having an evaporator comprising a casing adapted to contain a liquidv refrigerant said'casing having a heat reservoir `therein comprising a plurality of heat storage units separated by refrigerant chambers.

12. A plate evaporator comprising a casing having partitions therein orming sepa-. rate chambers containing refrigerant and heat storage 'liquid,and,` a cover connected to the walls of the casing and with the partitions. l

13. A plate evaporator comprising a cas-A ing builtup of separate members including atop and bottom, partitions therein forming with the top and bottom separatoree chambers, and means for securing to et erin -fluid tight relation separate memers of saidl evaporator. -1=1. A refrigerating machine having a los plate evaporator comprising a casing having artitions therein forming separate cham ers containing refri erant and heat storage liquid, and a cover aving a brazed connection with the walls of the casing and 4 Vwith the partitions, -v l 15. A. refrigerating machine having a plate evaporator comprising a casing built up of separate members including a top and a. bottom, and partitions therein forming with the top and the bottom separate refrigerator and heat storage chambers, said parts leng secured together in a fluid-tight manner by copper brazing.

16. A mechanically operated refrigeratng outfit having a chamberfrom which heat is to be extracted, a thin flat'horizontally disposed heat absorbing unit in said chamber,

A and a container for liquid in thermal proximity to said unit.

17 A mechanically operated refrigerating outfit ha ing a. chamber from which heat is to extracted, 'a thin flat horizontally disposed heat absorbing unit at one extremity of said chamber, and a container for liquids in thermal proximity to said unit.

18. A mechanically operated refrigerator having a' chamber with walls insulated against heat, a horizontally disposed freeze plate in said chamber adjacent one extremity thereof, and a container for liquid to be frozen in contact with said plate.

In witness whereof', I have hereunto set my hand this 17th' day of May 1926.

CHRISTIAN STEENSTRUP. 

